[api] Fix missing ifdef guards for AreaInfo and DeviceInfo messages

esphome/components/api/api_pb2.cpp

@@ -57,6 +57,7 @@ void ConnectResponse::encode(ProtoWriteBuffer buffer) const { buffer.encode_bool
 void ConnectResponse::calculate_size(uint32_t &total_size) const {
   ProtoSize::add_bool_field(total_size, 1, this->invalid_password);
 }
+#ifdef USE_AREAS
 void AreaInfo::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_uint32(1, this->area_id);
   buffer.encode_string(2, this->name);
@@ -65,6 +66,8 @@ void AreaInfo::calculate_size(uint32_t &total_size) const {
   ProtoSize::add_uint32_field(total_size, 1, this->area_id);
   ProtoSize::add_string_field(total_size, 1, this->name);
 }
+#endif
+#ifdef USE_DEVICES
 void DeviceInfo::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_uint32(1, this->device_id);
   buffer.encode_string(2, this->name);
@@ -75,6 +78,7 @@ void DeviceInfo::calculate_size(uint32_t &total_size) const {
   ProtoSize::add_string_field(total_size, 1, this->name);
   ProtoSize::add_uint32_field(total_size, 1, this->area_id);
 }
+#endif
 void DeviceInfoResponse::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_bool(1, this->uses_password);
   buffer.encode_string(2, this->name);

esphome/components/api/api_pb2.h

@@ -457,6 +457,7 @@ class DeviceInfoRequest : public ProtoDecodableMessage {
 
  protected:
 };
+#ifdef USE_AREAS
 class AreaInfo : public ProtoMessage {
  public:
   uint32_t area_id{0};
@@ -469,6 +470,8 @@ class AreaInfo : public ProtoMessage {
 
  protected:
 };
+#endif
+#ifdef USE_DEVICES
 class DeviceInfo : public ProtoMessage {
  public:
   uint32_t device_id{0};
@@ -482,6 +485,7 @@ class DeviceInfo : public ProtoMessage {
 
  protected:
 };
+#endif
 class DeviceInfoResponse : public ProtoMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 10;

esphome/components/api/api_pb2_dump.cpp

@@ -655,6 +655,7 @@ void DisconnectResponse::dump_to(std::string &out) const { out.append("Disconnec
 void PingRequest::dump_to(std::string &out) const { out.append("PingRequest {}"); }
 void PingResponse::dump_to(std::string &out) const { out.append("PingResponse {}"); }
 void DeviceInfoRequest::dump_to(std::string &out) const { out.append("DeviceInfoRequest {}"); }
+#ifdef USE_AREAS
 void AreaInfo::dump_to(std::string &out) const {
   __attribute__((unused)) char buffer[64];
   out.append("AreaInfo {\n");
@@ -668,6 +669,8 @@ void AreaInfo::dump_to(std::string &out) const {
   out.append("\n");
   out.append("}");
 }
+#endif
+#ifdef USE_DEVICES
 void DeviceInfo::dump_to(std::string &out) const {
   __attribute__((unused)) char buffer[64];
   out.append("DeviceInfo {\n");
@@ -686,6 +689,7 @@ void DeviceInfo::dump_to(std::string &out) const {
   out.append("\n");
   out.append("}");
 }
+#endif
 void DeviceInfoResponse::dump_to(std::string &out) const {
   __attribute__((unused)) char buffer[64];
   out.append("DeviceInfoResponse {\n");

script/api_protobuf/api_protobuf.py

@@ -995,6 +995,11 @@ def build_type_usage_map(
     }
 
     # Analyze field usage
+    # Also track field_ifdef for message types
+    message_field_ifdefs: dict[
+        str, set[str | None]
+    ] = {}  # message_name -> set of field_ifdefs that use it
+
     for message in file_desc.message_type:
         for field in message.field:
             type_name = field.type_name.split(".")[-1] if field.type_name else None
@@ -1007,6 +1012,9 @@ def build_type_usage_map(
             # Track message usage
             elif field.type == 11:  # TYPE_MESSAGE
                 message_usage.setdefault(type_name, set()).add(message.name)
+                # Also track the field_ifdef if present
+                field_ifdef = get_field_opt(field, pb.field_ifdef)
+                message_field_ifdefs.setdefault(type_name, set()).add(field_ifdef)
 
     # Helper to get unique ifdef from a set of messages
     def get_unique_ifdef(message_names: set[str]) -> str | None:
@@ -1032,9 +1040,16 @@ def build_type_usage_map(
             message_ifdef_map[message.name] = explicit_ifdef
         elif message.name in message_usage:
             # Inherit ifdef if all parent messages have the same one
-            message_ifdef_map[message.name] = get_unique_ifdef(
+            if parent_ifdef := get_unique_ifdef(message_usage[message.name]):
-                message_usage[message.name]
+                message_ifdef_map[message.name] = parent_ifdef
-            )
+            elif message.name in message_field_ifdefs:
+                # If no parent message ifdef, check if all fields using this message have the same field_ifdef
+                field_ifdefs = message_field_ifdefs[message.name] - {None}
+                message_ifdef_map[message.name] = (
+                    field_ifdefs.pop() if len(field_ifdefs) == 1 else None
+                )
+            else:
+                message_ifdef_map[message.name] = None
         else:
             message_ifdef_map[message.name] = None